Per Sage Advice, Otiluke's Resilient Sphere can stop someone who is grappled from continuing to be grappled.  I'm curious what other interactions could be inferred from this and from the spell's text.  If one creature is Tiny and the creature that Otiluke's is being cast on is Medium, could the Tiny size one fit in the component pouch or backpack of the creature getting the Sphere treatment and being included in the area of effect of ORS?  If not, does the accessory or article of clothing that contains the Tiny creature simply get forced off the Medium-sized creature?

It's a cute ruling, but Otiluke's Resilient Sphere doesn't say it pushes things away from the target that are already in its space, or breaks grapples, or anything like that, so Crawford is once again out on a limb. Certainly a target couldn't pass its hands through the sphere after it's cast to grapple someone, but there's no indication in the spell's text that they couldn't maintain their grip as the bubble springs up around their arm on an already maintained grapple. Would casting the sphere on a target that is bound and gagged cause the ropes to burst outwards on teh outside of the sphere? The targets clothes? The familiar in their backpack? If not, why would these be treated differently than an enemy that is in that space? 

If we're just coming up with other cute ideas for the spell which aren't necessarily RAW.... if the sphere traps air (despite allowing the target to breathe as normal) and doesn't allow new liquid in, you could probably use it to hamster ball across liquid surfaces. 

If the enclosed creature "can't be damaged by" things outside the sphere, can they drop themselves off of cliffs and bounce harmlessly when they land? One could argue that you take falling damage from hitting the inside of the sphere, not the ground, but you haven't really fallen in relation to the inside of the sphere, it could be flexy, it could just be *magic*, etc etc.... Otiluke's Drop Pod!

"The globe can be picked up and moved by other creatures" opens up playing relay with the enclosed character, in a way that isn't usually permitted RAW even with willing allies. Normally moving an ally around the battlefield involves either shoving them, or using your action to grapple them and then drag them at half speed... the sphere is "weightless," and doesn't suggest that it needs to be grappled in order to be "picked up," so allies with free hands may be able to just dash-run you around the battlefield, or even throw you? 

Playing off the inability of water to pass through it, the Sphere can be used as a temporary plug for a sinking ship, filling trap room, or the like.... or as a temporary bridge, if targeting a suitably-shaped large object that wouldn't be rigid/strong enough to trust your weight to normally. The rules are a little fuzzy about what constitutes a "large" object... is a 50' coil of rope larger when it is stretched out straight than coiled, because its length has changed? Or is size a measure of solid mass? If you can stretch out a rope 50', cast the "Sphere" on it to make a 50' rigid magical weightless tube, and then move that tube around while it maintains its shape... that has some possibilities. 

 Ok. How would you rule then? His first response is entirely correct, being grappled does not prevent you from being targeted by ORS, and that in itself creates the essential conundrum. Beyond that, it seems like everything Jeremy said is "technically correct," Jeremy comes just short of saying what you imply he does. "a classic use of the spell" might be referring to anything including previous editions. Any ruling between interacting game features that isn't called out by the rules is up to the DM. As far as I'm concerned, solving this conundrum is up to the DM, and ending the grapple seems the simplest and most balanced option between that and, say, shearing off the grappler's arms or including two creatures in a spell effect that clearly only targets one.

 As to the OP's question, as soon as you start ignoring rules about moving around other creatures, then really you are in the realm of houseruling anyway so it is up to the DM.

Considering that the bubble is 1) not that much bigger than the creature itself and 2) entirely weightless, I think that the most RAW ruling with zero speculation is that a grappled creature with a Sphere cast on it continues to be grappled, with the grappler now gripping their Sphere. 

The sphere is big enough to surround the creature. A person could easily grab another person, but many people can't palm a basketball. I would leave it up to the DM as to whether they would allow you to grapple the ORS. At the same time, if you concede that the grappling creature doesn't get its arms sheared off or get enveloped in the ORS, then why would you assume that it gets (for free) to grapple something different than it originally had grappled?

It is certainly a way to make a ruling, but not the one I'd choose.

The spell text literally says "Nothing—not physical objects, energy, or other spell effects—can pass through the barrier, in or out." If we take this to its realistic conclusion, any part of the grappling creature inside the resilient sphere would be severed from the rest of it.

The reasonable ruling is to say that, instead of being severed, those parts are just pushed outside the sphere. But there's no way to rationalize a continued grapple in context of the quoted sentence.

Imagine the skin you are holding expands and swells outwards, creating a new translucent magical bubble just large enough to enclose the creature within. Considering that it’s weightless, no harder to hold than a large beach ball or balloon I imagine, I don’t see that the spell requires the grappler to let go.

Or, some other rationalization. A grapple is not any particular hold on hair, clothes, limbs, or anything else: instead, it’s a Condition, which works in the way the condition and rule section on grappling defines, and ends when the condition or another ability says it ends. The sphere doesn’t say that it effects grapples, the things that it does say it does can be interpreted in a variety of ways, and whatever you may think “makes sense” or would be fun and creative, RAW it doesn’t do anything to grapples.

Quote from Chicken_Champ >>

Imagine the skin you are holding expands and swells outwards, creating a new translucent magical bubble just large enough to enclose the creature within. Considering that it’s weightless, no harder to hold than a large beach ball or balloon I imagine, I don’t see that the spell requires the grappler to let go.

What requires the grappler to let go is that, again, "Nothing—not physical objects, energy, or other spell effects—can pass through the barrier, in or out." The grappler's brain cannot send the signals to their hand to maintain their grip. The electrical signals cannot get through the sphere.

Or, your hand stays locked in place and in a rictus grasp, unable to release. Or, your hand goes numb, but the bubble won’t let you withdraw your hand, leaving their weightless Sphere stuck to you like a big boxing glove. Or, it could be your way, or a different way,  or almost anything at all that the DM thinks is fun. But as for what’s written, what’s RAW, the rule doesn’t say one way or another how it would mess with a pre-existing grapple, and the effects it does describe don’t demand an interpretation in a way that necessarily ends grapples, so anything you come up with other than “no effect” is a house rule going beyond the published spell.

Quote from Chicken_Champ >>

Or, your hand stays locked in place and in a rictus grasp, unable to release. Or, your hand goes numb, but the bubble won’t let you withdraw your hand, leaving their weightless Sphere stuck to you like a big boxing glove. Or, it could be your way, or a different way,  or almost anything at all that the DM thinks is fun. But as for what’s written, what’s RAW, the rule doesn’t say one way or another how it would mess with a pre-existing grapple, and the effects it does describe don’t demand an interpretation in a way that necessarily ends grapples, so anything you come up with other than “no effect” is a house rule going beyond the published spell.

Again, RAW is that "Nothing—not physical objects, energy, or other spell effects—can pass through the barrier, in or out." RAW, if you have a hand inside the spell's volume, your hand is severed, because that is the logical consequence of exactly what the published spell says. I'm not really against saying that it's a "house rule" to rule that, instead, you're simply pushed out of the volume, so I guess we can be on the same page.

Another question though, that I've seen both answers for on this forum, is whether or not things that have total cover from you are "within your reach." If one takes the stance that something is only within your reach if you can actually reach it (i.e. if it's not in total cover), then Otiluke's Resilient Sphere easily fulfills the specific end condition of Grappled. I myself do not take that stance, but it's something to think about.

[EDIT] Another point is that being grappled doesn't prevent the target of the spell from using their action to move the sphere, so if they do that, they obviously are moved out of the grappler's reach, necessarily taking any part of the grappler inside the sphere with them. The easiest way to disallow this dismemberment, which I kind of don't think the spell should be able to do, is to go with what we've agreed is a house rule.

I would argue that the dictionary definition of "enclosed," which is what the resilient sphere does to the target, meets the description of removing the target from the reach of a grappler which is the circumstance that breaks the grappled condition.

Quote from Ophidimancer >>

I would argue that the dictionary definition of "enclosed," which is what the resilient sphere does to the target, meets the description of removing the target from the reach of a grappler which is the circumstance that breaks the grappled condition.

I think that some people think "reach" refers only to the distance that you can make a melee attack, regardless of physical ability to reach (intentional word choice) the target. Under that definition, it would be difficult to make the same ruling. I will note that the rules do mention that there is a specific range at which you can make melee attacks but do not specifically define "reach" as only that particular distance without regard to physical capability.

I think this is a really simple thing to settle. If the target has to make a saving throw, so too, should another "unwilling" creature that is affected by the spell. For example, a creature unwilling to release it's grapple.

"A sphere of shimmering force encloses a creature or object of Large size or smaller within range. An unwilling creature must make a Dexterity saving throw. On a failed save, the creature is enclosed for the duration."

In the case of the hanger-on, a failed save on their part leads to the circumstances that Saga repeatedly quoted.

Wondering if you have someone in the sphere and hit the sphere with Thunderwave if the sphere itself would damage people behind it as the wave propels it? I know the inhabitants of the sphere wouldn't be damaged, but it seems like it could serve as a cage and projectile under the proper circumstances.